The invention concerns a measurement device for the determination of partial discharges within metal-encapsulated, compressed-gas-insulated high-voltage switchgear with a capacitive voltage divider, whose high-voltage capacitor is formed by an inner conductor mounted with insulation in a metal capsule and an electrode mounted with insulation in an opening in the capsule, and whose low-voltage capacitor is formed by the electrode and the edge of the opening in the capsule and which is connected by means of a measuring cable with a display and/or measurement device.
A measurement device of this kind is known from U.S. Pat. No. 3,939,412. In this device the insulator that supports the inner conductor is brought out through an opening in the metal capsule and the electrode is mounted on the outer shell of the insulator or within the vicinity of the opening in the capsule, coaxially with the inner conductor. As a display or measurement device for the detection of corona discharges, for which this measurement device is used, spray discharge detectors or oscillographs are employed, which are connected to the electrode and the ground connection of the metal capsule. Since the corona discharges to be measured are relatively powerful, the fact that the capacitance of the high voltage capacitor C.sub.H is relatively small compared with that of the low-voltage capacitor C.sub.N poses no problems for the measurement.
The purpose of the invention is to measure localized partial discharges inside a gas insulated metalclad switchgear by means of a capacitive voltage divider, where the tapping of the partial discharge pulses is to have a high upper cutoff frequency in the megahertz range, with a high division ratio C.sub.H /(C.sub.H +C.sub.N), since the rise time of these pulses is very small and it is nevertheless desired to obtain an accurate reproduction of the pulses.